Damn, I thought I replied to you on this! The stock Terraplane wheel does have a very narrow hub section, so it's axle is relatively short compared to other wheels. You probably won't find a wheel to fit the Terraplane's axle, off the shelf. I suggest looking around first for a hub for a spoked wheel that will fit your axle and bearings, then have it laced to an appropriate rim.
An alternate way to do this would be to get the wheel you want, then have a new axle machined to match the hub and bearings, then have that axle welded into the Terraplane's leading link. Any new wheel with a wider hub is almost sure to cause the tire to fit a bit farther outside the edge of the fender.
Now, about that brake! Probably going to have to have a new caliper mount made to position it correctly over the rotor on the new wheel, no matter which way you go.
I will go out on a limb here, Randy, and say that you should first try to find some local custom bike talent around you who can do this kind of mix/matching work. Most custom bike shops do this every day! But, if you can't get it done locally, send me your new wheel-of-choice and your leading link and I will send it all back ready to mount on your car. I have machining and welding capabilities and can make the axle. I can also have the caliper bracket ready for you to just put it all back together. I can fit it all together on my Terraplane to make sure it all works. Of course, extensive testing will need to be done, like months and months! Just kidding!

What do you plan to do with your original wheel? Wanna sell it?